My neighbors just gave me a sand filter - they decided they weren't going to mess with their above ground pool anymore, so they gave it to me. The filter is a hayward, don't know the model, might be as much as 18 years old (checked laterals and everything, excellent condition.) It has no pressure gauge, though. How could I install one? And if I don't, how do I tell I need to backwash, and how long should I do it for?
They had some sand already in the filter, but not much, and I put approx. 75 pounds of sand to get it about 3/4 full, so I would estimate it to be the 100lb size. I have a Hayward 1hp pump, and it doesn't seem to produce enough to run the auto-vac, although plenty to use the manual vac, and to circulate the water. Is this due to having too much sand, too small of a pump, needing more back washing, or what? When I was getting a lot of dust and algae (dead) out of the pool yesterday, suction at the vacuum went down a whole lot, but improved a lot after back washing for about 3 minutes.